Method of and apparatus for cracking petroleum products



. Mar. 13, 1923.

c.-KRo|-,| METHOD OF ANUAPPARATUS FOR CRCKING ETRLEUM PRODUCTS foil Filed'Feb. 4, 1919 sheets-sheet 1 g .MZDWWHm IDBI) mmmvfu ZDFUSMM mais,

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Mar. 13, 1923.

C. KROLL METHOD OF AND APPARATUS FOR CRAGKING PETROLEUM PRODUCTS- 2 sheets Original Filed 4,' 1919 Y' Patented hier. i3, i923,

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te ril-no 'anar oleic CORNELIUS KROLL, OF TULSA, OKLAHOBIA. 'v

Continuation of application Serial No. 274,850, filed February 4, 19H3.

This application filed Febr-.tary

9, 1920, Serial H0. I$57,339.

To aU who/mt may concern.'

Be it known that I, CORNELIUS KROLL, a citizen of the United States of America, a resident of Tulsa, in the county of Tulsa, State of Oklahoma, haye invented certain new and useful Improvements in Methods of and Apparatus forv Cracking Petroleum Products, of Which the following is a. full, clear,and exact description, reference being had to `the accompanying drawings, forming a part of this specification.

My invention relates to improvements in methods of and apparatus -tor cracking petroleum products, with special reference to the manufacture of Igasoline. ItI has in View to obtain product'sof lower boiling points from those heavier portions of petroleum or similar hydrocarbons that can only be obtained b v the destructive distillation ot' such portions. y

The commonly employed hydrocarbon, petroleum, is composed oi. a series of hydrocarbons principally of the paraiiin group, the chemical composition ot' which is designated by the general formula: -CJlgmT Each member of the series has a` different specific gravity and boiling point, the boiling point becomin,"r higher as the specific. gravity increases.

ln any chemical reaction there exists a' certain state or condition of equilibrium, and so. in the cracking .t actu of petroleum products or residua, has been veri'- i'ied by experimentat-ion, there will exist a certain state or condition of equilibrium. Forl example: ii a petroleum residuum is confined in an enclosed vessel which has neither an inlct or an outlet. and this vessel heated up so that the residuum inside the \'esscl\vas subjected to a temperature of Soll F.. and a pressure olf-80 pounds per sq.

in.` and maintained undeil these conditions 'lor an indefinite length ot' time` and `then allowed to cool. we would find upon examination otthe. residuum so treated that a certain amount ot' cracking had taken place. only to thc ponLhoVvei'er.where an equilibrium was 'reached between the dii't'crent. petroleum and pressure.

molecules. t'or that particular temperature bc disturbed b v the length otl time the rcsiduum would bc maintained at the above tenuuaaturc and pressure. once the equilibrium sfasreached.

ln other words, a certain amount of effectively transmit heat `duch ,equilibrium would not crackingwill take piace and further crack lng would cease unless the equilibrium were disturbed. This vequilibrium 1s not disturbed by continued maintenance of the residuum under pressure and temperature, but only by removing some of the elements entering into the equilibrium, allowing the reaction to proceed further until equilibrium is again restored. This Ais a very essential condition which must be obtained in an economic cracking process.

Another desirable condition to beattained is the removal of cracked residua and carbon from the reaction chamber so that its accumulations may not disturb the progress of the process.

Certain processes are carried on `in the gaseous phaseonly, but these have the great disadvantage of not vbeing able to disturb the equilibrium after a certain amount of cracking has been obtained andthe degree of cracking that takes place Without the' c 'ac-king reaction to the end by continually;

unbalancing the equilibrium ot the system .in the direction of :tui/ther and more complete cracking. the resulting product being only alow boilingu hydrocarbon, the residuum being a carbon sludge. Thus a com- )lete cracking reaction is obt ed, produc mg only the desired Aproduct 4and the *can bon sludge above-mentione l.

Another object of the invention isto very through theobody ot' liquid undergoing` treatment in a reac-` tion chamber, so` as to maintain the liquid at a cracking temperature Without undue heat losses. A further object is to eliminate the danger and trouble heretofore incurred by accumulations 0* carbonaceous residual mat ter on the surfaces from which heat is transmitted to the oil. Briey stated, the hydrocarbon liquid may be confined' under pres` sure in a reaction chamber lfrom which the light products are ,continually permitted to escape in the form of vapor, and the cracking temperature vmay be maintaineil by transmitting a heating medium. such flame and other hot products otA combos` My improved process operates in tion, through a .tlue passing through the body of liquid. This flue is surrounded by and in contact with the body of liquidi, the heat being transmitted from the outer -face of the flue to the surrounding liquid. By continually brushing, or scraping, said outer tace ol the lue, the heat 'transmitting tace can be lrept in a clean condition, tree of carbonaceous deposits, and these residual deposits will drop to inactive points at the bottom of the reaction chamber, Where they out of the sphere of action and from which'lmints they can be easily removed at the vwill of the operator. 1t will now be readily understood that the hydrocarbon liquidsurrounding the heating medium is very c tectivelv heated by the transmission ot heat 4from the clean outer tace of the line, and the residual matter dropping,r :from this face does not interfere With the transmission ot' heat to the liquid, nor with the intense cra-cking reaction 1which occurs at the tine.

liilith the foregoing and other objects in view, the invention comprises the novel construction, combination and arrangement of parts hereinafter more specifically described and illustrated in the accompanying dravw ings, wherein is shown the preferred emvbodiinent of the invention. However, it is (itl tio

to be understood that the invention comprehends changes, variations and' modications fvhich come within the scope of the claims hereunto appended.

liig. l is a side elevation, partly in section, illustrating a cracking apparatus ernbodying the features of this invention.

H is an enlarged longitudinal section taken approximately through the cen ter of the reaction chamber.

Fig. Hl is an enlarged transverse section oi" the reaction chamber.

Fig. lV is an enlarged fragmentary ver` tical section illustrating the elements near one end of the reaction chamber.

To illustrate one form ot' the invention, l have. shown a long cylindrical reaction chamber A mounted on supports 1 (Fig. l) whereby it is supported in an approximately horizontal position. 2 designates a vapor conductor leading trom the top of the reaction chamber. as shown in Fig. I, and 3 des` ignates an oil conductor through which a fresh charge may be delivered to the reac` tion chamber. il horizontally disposed tube, oriue 4. is located within the reaction chamber and secured atv its ends to in-.

Lafraise tlue through which products of combustion are discharged from the flue a, the reaction chamber being interposed between said heating` chamber 6 and outlet tlue 7. Sleeves 8, telescoping with the end portions of flue 4, serve as means for protecting` said end portions from direct contact with the llame and hot gases. A burner 9 (Fig. l), located at the heatingchamber t3, is adapted to discharge llame and hot lgases through the hea-ting' chamber 6 and also through the internal flue d, said flue i being open at both ends to provide for the admission and discharge of products by combustion.

lt will now be understood that the inter-- nal tine f1 is subjected to the intense heat of the flame and hot gases passing, from the burner 9, and that the heat is very effectively transmitted from the outer tace ot the internal flue to the surrounding body of oil in the reaction chamber. lt is notnecessary to transmit any heat through the bottom ot' the reaction chamber, in fact, all ot the exposed surfaces of said chamber are preferably Covered by an enclosing body of heat insulating material l0, shown in Fig. l.

To illustrate .a means for removing carbonaceous residual matter from the outer taceo` the internal liuc 4, ll have shown a rotatable frame consisting.;r ot' gear rings 11 arranged in the end portions of the reaction chamber and rotatably mounted on rolls 12, the latter beingf supported by threaded pins screwed into the castings 5; longV bars 13 connecting` the gear rings 11 and diagonal bars 111 serving as braces for the connecting` bars 13. The brushes, or Scrapers, 15 may be in the form` of sheet metal wings secured at'their outer margins to the connectin; 1i bars 13 and provided with scraping edges which engage the outer tace of the internal flue 4. as shown most clearly in Fig. lll. Springs 16 (Fig. lill) may be interposed bi tween the Scrapers 15 and bars 13 so as to yieldingrly force the Scrapers into engagement With the flue 1. The gear rings ll are concentric Withthe center line ottlue el, and

since the connecting bars 13 and Scrapers 15 are supported by these lcrear rings. it

will be apparent that a rotary motion of the (rear rings will cause the scrapers to travel 1n c1rcular paths around the outer 'tace ol' the flue 4. There are tour sets oi scrapers 15, each set being secured to one of the con-` necting bars 13, andl the scraper-s of the several sets are arranged in alternating relation so as to act upon the entire outer-tace of the tube 4.

The means for rotating the scrapingdei' vice or brushing' device comprisespinions 17 arranged within the reaction chamber andineshing. with the gear rings 11. said pinions being fixed to a drive shaft 18, one end ot Twhich is rotatably mounted in a bearltl While the 'opposite end extends Lafraise through a stuiing box 20 secured to the reaction chamber. In Fig. l, l have shown a gear Wheel 2l secured to the shaft- 18 for .the purpose of transmitting a rotary motion thereto. l/Vithin the reaction chamber, a bearing 22 (Fig. Il) is suspended from stay rods 23 having their ends secured to the ends of the reaction chamber.

To provide for the discharge of residuum from the reaction chamber (Fig. l) l have shown a closed residuum chamber 24 having an outlet 25 adapted to be closed by a valve 26, and a residuum conductor 27 leading from the bottom of the reaction chamber to the residuum chamber 24, said conduetor 27 having branches leading to different portions of the bottom of the reaction chamber and each of said branches being provided with avalve 28. 29 designates a valve located in the conductor 27.

When the apparatus is inservice, the contents of the reaction chamber are maintained under a high pressure, for example, about 80 pounds per square inch` and the carboiiaceous residuum can be easily removed Without materially lowering this pressure. When the outlet valve 26 (F ig. l) is closed to prevent the escape of fluid under pressure from the residuum chamber 24, the valves 28 and 29 may be opened to allow the residuuin in the bottom otl the reaction rliamber to bedischarged by the fluid pressure within said chamber. lIt this is done the residuiim Will tloivv through the conductor 27 and into the chamber 24 until the pressure in chamber 24 is equal to the pressure .in the reaction chamber, whereupon the valves 2S and 29 may be closed and the valvel 2li may be opened to discharge the residuuin troni chamber 24.

The reaction chamber is operated under pressure, depending upon the product to be treated, the average pressure being approximately 80 pounds per square inch, and the temper Iure of the contents of the `reaction chamber is maintained at such a degree (approximately 700 F. to 800O F.) as to cause distillation at the pressure maintained, distillation under suchconditions being a dcstru'ctiif'e distillation resulting in cracking of the heavy hydrocarbon which is forced into the reaction chamber through the inlet pipe 3, shown in Fig. l. The light h vdromrbons resulting from the cracking reaction are continually discharged through the vapor pipe 2'. and the residuuni may bc drawnol at intervals through the valves 28 and. 2S), as previously pointed out. The operation is thus rendered continuous and thel entire system is a comparatively simple apparatus Within the control of the operator at all ltimes'. I do not deem itnecessary to show the dephlegmator, condenser Aor pressure 'regulating valve usually -found in an apparatus ofthis kind, for all ot' these elements are old and' Well understood in this art.

The flue 4 .is separated trom the bottom of the reaction chamber to provide for the accumulation of carbonaceous' matter at points entirely belou1 the flue, and the scraping devices engaging the outer faces ot' thc line may' be rotated continually to remove the carbonaceou's matter which drops `to the bottom of the reaction chamber where it will not in any way interfere with the transmission of heat to the oil. Furthermore, `this residual matter is not disturbed or agitated by the thermo-circulation resulting from the transmission of heat from the internal flue. to the oil. The oil contacting with the outer face of the flue 4 is constantly' rising and being replaced by comparatively cool oil, so the entire body of oil is ,very ei'ectively maintained at a high temperature by the heat transmitted from the outer face ot i ing part of the new apparatus, l will state' WithoutI in any way limiting the scope ot' the claims that the-reaction chamber may be 6g feet in diameter and twenty feet long; the internal flue 4 may be 20 inches in diameter. I'n the treatment of gas or fuel oil to obtain a product having an end point lower than 460O F., t-he contents of the reaction chamber may be maintained at a temperature say up to 800o F. and under a pressure up to about 80 pounds per square inch. The level of the liquid should be maintained entirely above the flue 4, as suggested by Fig. lll. The reaction chambei' may be provided with a manhole normally closed by a cover 30, shown in Fig. III. l

This application is a continuation of my prior application Serial No. 274.950, filed 'February 4, l1919.

l claim: i

l. The methodV ot manufacturing petroleum products consisting in subjecting a body of suitable liquid hydrocarlmii to be treated Within an enclosed reaction chamberunder pressure to an internal source ol heat surrounded by tlie'liquid hydrocarbon so as to effect cracking and the distillation and separation olg the lighter products produced.

removing the lighter products as the).vv arc 2. In the art of cracking hydrocarbons,-

the method which comprises confining :i

body of the hydrocarbon liquid to be cracked 1n al reaction chamber, transmitting heating iframes i matter at points entirely below said flue, and a scraping device engaging said outer face of the flue to continually remove carbonaceous matter therefrom, said scraping de vice comprising a scraper-carrying frame surrounding said flue, and means for rotating said frame to revolve its scraping ele.u

ments around the axis of said iiue. y

10. In an apparatus for cracking petroleum hydrocarbons, a reaction chamber wherein a body of hydrocarbon liquid is maintained under pressure, a flue passing through said vreaction chamber below the level of the liquid therein,the outer face of said iuebeing directly exposed to the surrounding liquid, means for heating said flue so as to subject the liquid to heat trans#y mitted from said outer face,- said due being] separated from the bottom of said reaction chamber to provide for the4 accumulation of carbonaceous matter at points entirely below said flue, and a scraping device engaging said outer face of the ue to continually remove carbonaceous matter therefrom, said scraping device comprising ring-gears surrounding end portions of said flue, scraper als supporting members connecting said gears, andv driving pinions Vmeshing withsaid gears. WM" A 11. In anapparatus for cracking petroleum hydrocarbons, a reaction chamber 4wherein a body of hydrocarbon liquid is' maintained under pressure, an approximately horizontal iiue extending through said reaction chamber below the level of the li uid therein, the outer face of said flue being directly exposed to the surrounding liquid, a source of-heat from which hot products of combustion are transmitted through said flue so as to subject the surrounding liquid to heat transmitted from-the outer face of the flue, said approximately horizontal flue being separated from the bottom of said reaction chamber to provide for the accumulation of carbonaceous matter at points entirely below said flue, and a scraping device rotatable around-,said ilue and engaging the outer face thereof to continually remove c arbonaceous matter therefrom.

12. In an apparatus for cracking petroleum hydrocarbons, a'large cylindrical horizontally disposed reaction chamber wherein a body of hydrocarbon liquid is inain' tained under pressure, heat insulating material enclosing said reaction chamber, an open ue extending from one end oit said reaction chamber to the other, said iiue being in an approximately horizontal position below the level of the liquid and above the hotremoved from the reaction chamber, ,a scraping. device engaging the said outer face of the iiue, and means for rotating said scraping device 'around said flue to continually` remove carbonaceous matter therefrom.

13. In an apparatusfor cracking petro- Ileum hydrocarbons, a reaction chamber wherein a body of hydrocarbon liquid is maintained under pressure, a flue passing through said reaction chamber below the level of the liquid therein, the outer face or said flue being directly exposed to the surrounding liquid, means for heating said ilue so as to subject Vthe liquid to heat transmitted from said outer face, the bottom of said reaction chamber having an inactive surface, means whereby carbonaceous matter is continually removed from said outer face and dropped onto said inactive surface, a residuum conductor leading from the bottom of said reaction chamber to provide for the discharge of said carbonaceousmatter, and a valve controlling the discharge through said conductor,

14. In an apparatus for cracking petro- D leum hydrocarbons, a reaction chamber wherein a body of `hydrocarbon liquid is maintained under pressure, a flue passing through said reaction chamber below the level of the liquid therein, the outer face of said ilue being directly exposed to the surrounding liquid, means for heating said lue so as to subject the liquid 'to heat transmitted from said outer face,` the bottom of said reaction chamber being separated Jfrom said flue so as to be entirely beyond the means for heating the liquid, means whercby carbon'aceous matter is continually .re-4

moved from said outer face and permitted to drop to the bottom of said reaction chamber, a residiiun chamber connected to different portions of the bottom of said reaction chamber, 'a valve controlling the escape of fluid` under pressure from said residuum chamber, and a valve adapted to control communication between said reaction chamber and residuum chamber.

dn testimony that I claim the foregoing I hereunto amr mv signature'.

A conunnrus xsone. 

